Siglent SDS800 Zoom out question (problem?)

[electr_peter]

Who is using straw arguments here exactly? Let's burn some straws:

@2N3055's flawed argument - Keysight's "zoom out" should do miracles to get data around already captured on screen data in RUN mode (which in this context is not possible with normal scope). Additional capture around screen occurred later in STOP mode, thus no miracle occurred, thus "zoom out" is not useful. Q.E.D.

This is slander and complete lie. I never said that.
You are now lying and inventing what people said to prove you are right.
I said  Keysight memory management when going into stop is not doing what most people think it does.

Keysight does NOT do what you claim it does.
After stopping, you DO NOT have insight into what was around event that was on screen when you pressed STOP.
It does not "zoom out". It takes separate, later capture, at some completely different time, and shows you what was around that later event.

Both ways you will get some random capture later.

It is a trick and gives you absolutely the same result as "change timebase-stop" on all other scopes.
"Zoom out" specifically means to be able to show data before and after the actual event on the screen.
Keysight implementation does not do that. It haven't got "zoom out". Period. It is misleading, QED.

You imply multiple times that Keysight should work in "zoom out ultra" mode (as if it was advertised/guaranteed to do that, where?) but actually works in "zoom out plus" mode which is a trick/not "zoom out"/cheat/misrepresentation/lie and not even useful according to you. You always mention "capture later" thing as an extreme disadvantage. "zoom out plus" version specifics and benefits are very clear, that is exactly what Keysight does and says it should do. Yet you keep claiming otherwise.

You know much better than me that normal scope would be a molten puddle of gold (in terms of calculation power and cost) to be able to pull of "zoom out ultra" functionality. Which only differs from "zoom out plus" in corner cases, but at massive extra cost. And even if scope could do this, this zoom out thing would be on the very last page of new features, anyway.

You obviously agree there is "zoom out plus" functionality. If you say you don't use it much and or see much value in it, fine, I never had problem with this. But if you say it has no benefit at all in principle, you are blind.
Other function suite is mostly orthogonal to "zoom out plus", you can have one, other or both at the same time. But please don't spread BS as such feature has obvious value in some circumstances for other users.

[Someone]

There are two straight out lies which are being raised here once again:
Claiming that if you don't blindly capture around the screen then you will have to capture again. Despite that you can capture the entire interesting data without having to capture around the screen.

You move around the issue.
If STOP capture was made and was deemed to be too short, then with "zoom out plus" you may not need to make a new capture. With other scopes you do, there is no way out of this situation.

You can keep saying there is no possible way to achieve the same result, and we'll keep saying it is trivial.

a) Set the horizontal time base to the period you want to have captured. If you want a narrower/magnified view on the screen enable the zoom.
b) Same resulting capture as capturing around the screen (assuming they are set to the same memory depth).
c) Same resulting capture as the bonus capture some keysight models make when pressing stop (assuming they are set to the same memory depth).

If instead you have now moved the goalposts and are going to claim that this is all about the bonus (unreliable) Keysight capture on stop, then you need to say that upfront. Notice how I was not talking about c) but the comparison of a) and b).

@Someone's flawed argument - user always knows best capture settings for each possible signal in advance and can do perfect capture on 1st try. It is not possible for user to select wrong settings, have doubts, second thoughts or additional insights in the process because all is known in advance. Thus no recapture is needed, ever. Thus "zoom out" has no value and can be ignored. Q.E.D.

If a user has set their scope to capture around the screen then they have explicitly made that choice (and the downsides it brings), which could equally capture the exact same data by using a longer horizontal sweep. Either way the user had to choose what horizontal capture period they wanted.

The comparison is what those two capture methods trade off, how they compare.

The Keysight bonus capture on stop, only captures repeating triggers that occur in a tiny window of time after the user presses stop. It is not a general solution for users wanting to capture data around a (low repetition) trigger in run mode.

[electr_peter]

There are two straight out lies which are being raised here once again:
Claiming that if you don't blindly capture around the screen then you will have to capture again. Despite that you can capture the entire interesting data without having to capture around the screen.

You move around the issue.
If STOP capture was made and was deemed to be too short, then with "zoom out plus" you may not need to make a new capture. With other scopes you do, there is no way out of this situation.

You can keep saying there is no possible way to achieve the same result, and we'll keep saying it is trivial.

You are miss-reading my post and giving completely different meaning. I do not say anywhere that the is no alternative ways to achieve the same result (which should be even more clear if you read my post context with several following sentences which you didn't quote here).
I said that in specific circumstances without "zoom out" scope user is more limited than otherwise. Please read this conditional statement with clarifying comments carefully:

If[conditional] STOP [all capturing stopped] capture was made and was deemed to be too short [[1us display] only], then with "zoom out plus" you may not need to make a new capture [because there is memory beyond [1us display] and by increasing timebase you can see [100us display]]. With other scopes you do [need to enable RUN/SINGLE again and make new capture with longer timebase], there is no way out of this situation [other than new capture, because you cannot expand current [1us dislay]].

This is the main benefit. Also, if STOP happened to capture the very last occurrence of anomaly, you are SOL without "zoom out plus" (anomaly will not repeat, so you are stuck with limited [1us display] instead of full memory).

...the bonus (unreliable) Keysight capture on stop...

Keysight feature is not unreliable, that is not what the word "unreliable" means. On scope it works according to the same logic every time. Signal and trigger conditions affect final result, but that is not "unreliable". If scope BSOD'ed or showed different results for the same conditions, that would be unreliable.

The Keysight bonus capture on stop, only captures repeating triggers that occur in a tiny window of time after the user presses stop. It is not a general solution for users wanting to capture data around a (low repetition) trigger in run mode.

In such case user can press SINGLE, then scope will wait as long as needed to trigger and get full memory capture. Immediate benefit. Other ways to adjust scope settings are available, it is up to the user to find adequate setting.
Also, "zoom out plus" is not a general solution, nobody claims that. Primarily because word "solution" is not equal in meaning to "functionality". It is a bonus (your words) or a refined feature.

You seem to assign alternative meanings to words "if", "achieve", "(re)capture", "solution", "unreliable" and miss-read clear statements to give them opposite meaning. Considering your username I feel like a character in the legendary sketch "Who’s on First?" — Abbott and Costello
Maybe this leads to unfounded and incorrect assumption that Keysight functions in "zoom out ultra" mode (that would be super nice, BTW). "zoom out plus" is implemented as advertised and is a bonus nevertheless.

[KungFuJosh]

4 guys from different countries including Lithuania, Croatia, Australia, and the Netherlands walk into a forum and argue semantics in English... 

[2N3055]

 

4 guys from different countries including Lithuania, Croatia, Australia, and the Netherlands walk into a forum and argue semantics in English... 

[electr_peter]

I should really get heavy machinery operator license to use excavator instead of shovel to dig through thick layers of BS. Readers can make conclusion for themselves as a HW exercise.

There is so much both educational and entertaining material on scope technology, semantics and other relevant topics on this forum - where else would one find such a broad scope (pun intended)?

[tautech]

I should really get heavy machinery operator license to use excavator instead of shovel to dig through thick layers of BS. Readers can make conclusion for themselves as a HW exercise.

There is so much both educational and entertaining material on scope technology, semantics and other relevant topics on this forum - where else would one find such a broad scope (pun intended)?

One might suggest such investment is better spent on visionary aids.

[electr_peter]

I should really get heavy machinery operator license to use excavator instead of shovel to dig through thick layers of BS. Readers can make conclusion for themselves as a HW exercise.

There is so much both educational and entertaining material on scope technology, semantics and other relevant topics on this forum - where else would one find such a broad scope (pun intended)?

One might suggest such investment is better spent on visionary aids.

Don't forget reading aids

[Someone]

...the bonus (unreliable) Keysight capture on stop...

Keysight feature is not unreliable, that is not what the word "unreliable" means. On scope it works according to the same logic every time. Signal and trigger conditions affect final result, but that is not "unreliable". If scope BSOD'ed or showed different results for the same conditions, that would be unreliable.

If it is reliable and follows the same logic, where is this logic documented or explained? The time period that it will make the bonus capture is very small, and it relies on more triggers arriving. Same as your next "solution" you proposed. And this is only some Keysight scopes, can you name which ones do and which ones dont? I only know 3 models which do and several models which dont and am unaware of any list or clear documentation.

There are two straight out lies which are being raised here once again:
Claiming that if you don't blindly capture around the screen then you will have to capture again. Despite that you can capture the entire interesting data without having to capture around the screen.

You move around the issue.
If STOP capture was made and was deemed to be too short, then with "zoom out plus" you may not need to make a new capture. With other scopes you do, there is no way out of this situation.

You can keep saying there is no possible way to achieve the same result, and we'll keep saying it is trivial.

You are miss-reading my post and giving completely different meaning. I do not say anywhere that the is no alternative ways to achieve the same result (which should be even more clear if you read my post context with several following sentences which you didn't quote here).
I said that in specific circumstances without "zoom out" scope user is more limited than otherwise. Please read this conditional statement with clarifying comments carefully:

You added the context later and are trying to drive the conversion to one single point that is not explained or motivated, still you add more noise than explanation. Also cutting out of your quote where I separate the ideas so people can discuss it without all the confusion or the new terms you decided to "define" with bold.

a) Set the horizontal time base to the period you want to have captured. If you want a narrower/magnified view on the screen enable the zoom.
b) Same resulting capture as capturing around the screen (assuming they are set to the same memory depth).
c) Same resulting capture as the bonus capture some keysight models make when pressing stop (assuming they are set to the same memory depth).

Right now you seem stuck on c) which is ok, just say it clearly that you think the Keysight additional (possible) capture on stop is a way you think people should consider. I argue since it is undocumented and only works in narrow circumstances it is poorly comparable to a) or b) which will reliably capture a longer period around a trigger.

[electr_peter]

Descriptions are in user guides, app notes, etc. (i.e. spread in parts all over the place). To be honest, no feature of a scope is described in detailed enough way (due to many reasons) to satisfy your needs or level of this thread. If you want all the details, do research yourself.

Official list of "zoom out" scopes doesn't exist. To my knowledge, "zoom out" is available on all Keysight InfiniVision models (X1/2/3/4/6k), the new HD3 and likely all older models with MegaZoom chip (including older ones from 1990s). Other Keysight series most likely not. Some say Rigol models also have "zoom out".

You don't fully understand "zoom out" function, thus are not keen on using it. That's is fine with me. Not going to argue various quote misrepresentations.

[nctnico]

Descriptions are in user guides, app notes, etc. (i.e. spread in parts all over the place). To be honest, no feature of a scope is described in detailed enough way (due to many reasons) to satisfy your needs or level of this thread. If you want all the details, do research yourself.

Official list of "zoom out" scopes doesn't exist. To my knowledge, "zoom out" is available on all Keysight InfiniVision models (X1/2/3/4/6k), the new HD3 and likely all older models with MegaZoom chip (including older ones from 1990s). Other Keysight series most likely not. Some say Rigol models also have "zoom out".

Having had quite a few DSOs from various brands through my hands over the past decades, I can say that all DSOs made by mainstream brands except for true Lecroy models (not the rebadges from Iwatsu) and some older Siglent models, can zoom out (capture beyond the screen if memory length permits). IOW it would be an extreme rarity to find a DSO which can't zoom out as it is as standard like having a voltage meter on a bench power supply. This has been explained in great detail and length in a previous thread which seemed to have been 'forgotten' by some. So it is better to create a list with DSOs which can't zoom out. It will be pretty short.

[Someone]

Descriptions are in user guides, app notes, etc.

If the documentation does exist are and you like the Keysight bonus capture when pressing stop, then why cant you point to the documentation of it?

Actual serious question. I have made efforts to find such documentation and failed. Here is your chance to show how I'm not good at finding information and you are better at it. Share this secret knowledge for the benefit of everyone.

[Someone]

Descriptions are in user guides, app notes, etc. (i.e. spread in parts all over the place). To be honest, no feature of a scope is described in detailed enough way (due to many reasons) to satisfy your needs or level of this thread. If you want all the details, do research yourself.

Official list of "zoom out" scopes doesn't exist. To my knowledge, "zoom out" is available on all Keysight InfiniVision models (X1/2/3/4/6k), the new HD3 and likely all older models with MegaZoom chip (including older ones from 1990s). Other Keysight series most likely not. Some say Rigol models also have "zoom out".

Having had quite a few DSOs from various brands through my hands over the past decades, I can say that all DSOs made by mainstream brands except for true Lecroy models (not the rebadges from Iwatsu) and some older Siglent models, can zoom out (capture beyond the screen if memory length permits). IOW it would be an extreme rarity to find a DSO which can't zoom out as it is as standard like having a voltage meter on a bench power supply. This has been explained in great detail and length in a previous thread which seemed to have been 'forgotten' by some. So it is better to create a list with DSOs which can't zoom out. It will be pretty short.

Your own words on this from the mega thread that people seem to refuse to read/remember:

Again (4th time I'm explaining this): Keysight has changed the behaviour on the more modern models!

So no, not all scopes from all brands other than Lecroy and Siglent. Also some scopes from Keysight.

You might argue some of those Keysight models dont zoom out (fair enough if we use your consistent definition of zoom out) and simultaneously electr_peter is claiming they do the best zoom out ever.

Alternative method you both seem to get defensive about: pretty much all scopes (including the ones you separate out) can achieve a comparable result by zooming in before capturing.

Anyone trying to clearly explain this gets dumped on with the pile of noise and fake argument rather than polite discourse.

[awakephd]

SDS800xHD has 2 memory modes: Auto and fixed sample rate.

I have no dog in this fight, but did want to "zoom in" on the above comment. (Yes, dreadful pun, but I can't truly say I'm sorry!)

I am still learning my way around the SDS800X HD - enjoying the scope very much, and finding it to have capabilities comparable to the Keysights in the lab at the university where I teach (I don't teach in the engineering school, but I'm sitting in on an EE course) - so always interested when I see something I haven't yet noticed or understood in its capabilities. I confess I am still working my way through the manual ... slowly ... and through the massive performance and review thread that was referenced above ... slowly ... so likely the answer is there.

But if anyone would like to give me a quick hint or reminder - where can I select between the auto and fixed sample rate, and when would I want to?

[Someone]

But if anyone would like to give me a quick hint or reminder - where can I select between the auto and fixed sample rate, and when would I want to?

It is similar/related to setting the memory depth manually. For some captures you intentionally want fewer sample points, a common case is when offloading for later analysis. The scope can use its fast acquisition hardware to reduce the data to a suitable sample rate so that other systems downstream can operate faster.

You could also use it to manipulate the waveform update rate if that is something you care about.

[awakephd]

Thanks for the quick response! I had to chuckle - I asked if "anyone" would be willing to give me a hint ... and I got "Someone"!

[electr_peter]

Share this secret knowledge for the benefit of everyone.

Keysight documentation is not up to your standard of details (w.r.t. zoom out question) because is in pieces over multiple sources, dosed in MegaZoom marketing, etc. I am not going to do research for you to miss-interpret it. There is more than enough info in this thread.

Alternative method you both seem to get defensive about: pretty much all scopes (including the ones you separate out) can achieve a comparable result by zooming in before capturing.

You constantly move focus in other direction rather than focus on the topic matter for once. Due to interruptions you don't see the point straight.

[electr_peter]

Descriptions are in user guides, app notes, etc. (i.e. spread in parts all over the place). To be honest, no feature of a scope is described in detailed enough way (due to many reasons) to satisfy your needs or level of this thread. If you want all the details, do research yourself.

Official list of "zoom out" scopes doesn't exist. To my knowledge, "zoom out" is available on all Keysight InfiniVision models (X1/2/3/4/6k), the new HD3 and likely all older models with MegaZoom chip (including older ones from 1990s). Other Keysight series most likely not. Some say Rigol models also have "zoom out".

Having had quite a few DSOs from various brands through my hands over the past decades, I can say that all DSOs made by mainstream brands except for true Lecroy models (not the rebadges from Iwatsu) and some older Siglent models, can zoom out (capture beyond the screen if memory length permits). IOW it would be an extreme rarity to find a DSO which can't zoom out as it is as standard like having a voltage meter on a bench power supply. This has been explained in great detail and length in a previous thread which seemed to have been 'forgotten' by some. So it is better to create a list with DSOs which can't zoom out. It will be pretty short.

"zoom out" has few flavors (described here). Many scopes have "zoom out basic" by setting (in auto or manual selection) memory size to capture beyond display. For scope to not even have "zoom out basic" is mind-boggling (for example, Siglent SDS800X HD and SDS1000X HD(?)). "zoom out plus" is a refinement for max performance (found only in MegaZoom scopes AFAIK).

[electr_peter]

But if anyone would like to give me a quick hint or reminder - where can I select between the auto and fixed sample rate, and when would I want to?

It is similar/related to setting the memory depth manually. For some captures you intentionally want fewer sample points, a common case is when offloading for later analysis. The scope can use its fast acquisition hardware to reduce the data to a suitable sample rate so that other systems downstream can operate faster.

You could also use it to manipulate the waveform update rate if that is something you care about.

With Siglent SDS800X HD, press front panel button Acquire -> Memory Management settings -> [Auto] OR [Fixed Sample Rate]. [Auto] is for general use. Max Mem Depth value only matters for slow timebases - to get more data (at high sample rate) OR to speed scope (as low sample rate). [Fixed Sample Rate] is the same thing from a different angle, allowing to set sample rate directly for specific uses.

Always check bottom right corner for actual sample rate & memory status.

[Someone]

Alternative method you both seem to get defensive about: pretty much all scopes (including the ones you separate out) can achieve a comparable result by zooming in before capturing.

You constantly move focus in other direction rather than focus on the topic matter for once. Due to interruptions you don't see the point straight.

ha ha ha, OP literally asked if zoom out was some feature they would miss. How is suggesting an almost identical alternative moving the focus?

The OP repeated the misleading statement that:

Sure there are workarounds, like recapturing using a longer sweep rate, but I have found that annoying over the years.

Which is untrue, as a scope which cannot "zoom out" does not imply/mandate that the user must recapture. It is about setting the scope to capture what you want in advance. Same is true of any of the methods other than the bonus (undocumented, unreliable) feature which some Keysight models have.

[Someone]

Thanks for the quick response! I had to chuckle - I asked if "anyone" would be willing to give me a hint ... and I got "Someone"!

Brings a chuckle to me all the time too

[electr_peter]

OP literally asked if zoom out was some feature they would miss. How is suggesting an almost identical alternative moving the focus?

OP may miss feature in specific conditions. Mentioning similar (in general case) features (which are not equivalent in specific conditions) doesn't address the question properly. Saying to go around the problem is not a solution of how to solve a problem.

The OP repeated the misleading statement that:

Sure there are workarounds, like recapturing using a longer sweep rate, but I have found that annoying over the years.

Which is untrue, as a scope which cannot "zoom out" does not imply/mandate that the user must recapture. It is about setting the scope to capture what you want in advance.

OP stated clear opinion about scope features based on extensive experience and you dismiss that right away with the same misdirection as always Have you even used MegaZoom? If not, stop misrepresenting it as that's not helpful to anyone. Besides, you are flogging one week old post while saying nothing new.